A large quantity of epidemiological data has accumulated attesting to a link between social support and the progression of cardiovascular disease in cardiac patients. One way that social support might exerts its health effects is by attenuating physiological responses to psychological stress, since these responses have been related to cardiovascular disease. Much myocardial ischemia occurring during daily life appears to be related to periods of psychological stress, and laboratory mental stress tasks have been found to induce ischemia. Thus, the incidence, severity and duration of myocardial ischemia might be modified by changes in the social environment. Accordingly, this research will examine the role of social support in attenuating ischemic responses to psychological stress, both in the laboratory and during daily life. In the first study of this proposal, we will test the hypothesis that the presence of a supportive spouse attenuates ischemic responses to psychological stress in the laboratory. Using a counterbalanced crossover, repeated measures design, patients will be asked to complete a public speaking task in the laboratory in two conditions: with a spouse present; and alone. We will assess hemodynamic, radionuclide angiographic, and catecholamine responses to the task in both conditions. In the second study of this proposal, we will examine whether married patients show reduced duration of ischemia compared to unmarried patients. In addition, we plan to examine whether presence of a supportive other (spouse, or friend in the case of unmarried patients) reduces the incidence and duration of ischemia in patients, during daily life activities. Patients will be asked to keep a detailed diary for a two week period to ascertain patterns of daily activities. Using these diaries and in consultation with patients, we will select a two day period during which patients have a busy and varied schedule. Patients will then be asked to follow the same pattern of activities for a 48 hour period on two consecutive weeks when heart rate, and the incidence and duration of ischemia will be measured. During one week their spouse, in the case of married patients, or friend, in the case of unmarried patients, will be present; during the other week patients will be asked to repeat the activities alone. Taken together, these will be first studies to examine whether ischemic responses to psychological stress can be directly modified by psychosocial factors, and will provide important information about potential psychosocial interventions in patients with coronary artery disease.